Short-term effects on bone turnover of replacing milk with cola beverages: a 10-day interventional study in young men

Osteoporos Int. 2005 Dec;16(12):1803-8. doi: 10.1007/s00198-005-1935-z. Epub 2005 May 11.


In the Western world, increased consumption of carbonated soft drinks combined with a decreasing intake of milk may increase the risk of osteoporosis. This study was designed to reflect the trend of replacing milk with carbonated beverages in a group of young men on a low-calcium diet and studies the effects of this replacement on calcium homeostasis and bone turnover. This controlled crossover intervention study included 11 healthy men (22-29 years) who were given a low-calcium basic diet in two 10-day intervention periods with an intervening 10-day washout. During one period, they drank 2.5 l of Coca Cola per day and during the other period 2.5 l of semi-skimmed milk. Serum concentrations of calcium, phosphate, 25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol (1,25(OH)2D), osteocalcin, bone-specific alkaline phosphatase (B-ALP) and cross-linked C-telopeptides (CTX), plasma intact parathyroid hormone (PTH) and urinary cross-linked N-telopeptides (NTX) were determined at baseline and endpoint of each intervention period. An increase in serum phosphate (P<0.001), 1,25(OH)2D (P<0.001), PTH (P=0.046) and osteocalcin (P<0.001) was observed in the cola period compared to the milk period. Also, bone resorption was significantly increased following the cola period, seen as increased serum CTX (P<0.001) and urinary NTX (P<0.001) compared to the milk period. No changes were observed in serum concentrations of calcium or B-ALP. This study demonstrates that over a 10-day period high intake of cola with a low-calcium diet induces increased bone turnover compared to a high intake of milk with a low-calcium diet. Thus, the trend towards a replacement of milk with cola and other soft drinks, which results in a low calcium intake, may negatively affect bone health as indicated by this short-term study.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Alkaline Phosphatase / blood
  • Animals
  • Biomarkers / blood
  • Bone and Bones / metabolism*
  • Calcifediol / blood
  • Calcitriol / blood
  • Calcium, Dietary / administration & dosage*
  • Calcium, Dietary / metabolism
  • Carbonated Beverages*
  • Collagen / blood
  • Collagen Type I
  • Cross-Over Studies
  • Diet / adverse effects*
  • Homeostasis / physiology
  • Humans
  • Male
  • Milk*
  • Osteocalcin / blood
  • Osteoporosis / blood
  • Osteoporosis / etiology
  • Parathyroid Hormone / blood
  • Peptides / blood
  • Phosphates / blood


  • Biomarkers
  • Calcium, Dietary
  • Collagen Type I
  • Parathyroid Hormone
  • Peptides
  • Phosphates
  • collagen type I trimeric cross-linked peptide
  • Osteocalcin
  • Collagen
  • Alkaline Phosphatase
  • Calcitriol
  • Calcifediol